Longitudinal folding formers are well known, see the literature reference A. Braun: "Atlas des Zeitungs- und Illustrationsdruckes" ("Atlas of Newspaper and Magazine Printing"), Frankfurt am Main, 1960, page 66, in which the folding former can be pivotably adjusted over a predetermined angular range. Proper operation of the folding former requires that the upper end thereof is placed as closely as possible tangentially to the periphery of a driven supply roller as shown, for example, in FIG. 81-II of the literature reference, and that the tip or apex of the folding former triangle is, at all times, as close as possible above the axial level of a pair of transversely positioned, mutually parallel pull-off rollers, as illustrated in FIG. 81-III of the literature reference.
Certain production arrangements of printed material on webs require a shift of the tip of the folding former horizontally. This shift can be obtained by pivoting the folding former. In a pivoting arrangement in accordance with the prior art, substantial vertical shift of the tip or nose or apex of the folding former triangle will result, coupled with a horizontal shift of the upper or inlet portion of the folding former. To provide proper alignment with the associated former rollers, namely the supply roller and the pull-off rollers, it previously was customary to reposition the axes of rotation of the supply roller and/or the pull-off roller pair, to provide for the required correction. Repositioning of roller axes is complex and expensive.